Income Taxes - Schedule of Components of Deferred Tax Assets and Liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Deferred tax assets:
Net operating loss and tax credits carryforwards	$ 530,647	$ 727,213
Depreciation	57,752	81,194
Deferred revenue	17,544	56,004
Allowance for doubtful accounts	23,515	21,069
Deferred compensation	24,645	30,677
Unrealized loss	75,324	74,982
Nondeductible reserves	42,275	40,584
Interest	16,741	17,652
Operating lease asset	236,084	0
Total deferred tax assets	1,024,527	1,049,375
Deferred tax liabilities:
Investment in subsidiaries	84,880	97,208
Amortization of intangible assets	258,852	253,147
Operating lease liability	230,855	0
Other	1,260	1,829
Total deferred tax liabilities	575,847	352,184
Net deferred tax assets	448,680	697,191
Valuation allowance for net deferred tax assets	(541,641)	(778,262)
Net deferred tax liabilities	$ (92,961)	$ (81,071)